Re: unconfiguring swap at shutdown

[Manuel Bouyer <bouyer%antioche.eu.org@localhost>]

On Wed, Sep 03, 2008 at 03:11:45PM +0000, Christos Zoulas wrote:
> In article <20080903150644.GA26637%asim.lip6.fr@localhost>,
> Manuel Bouyer  <bouyer%antioche.eu.org@localhost> wrote:
> >On Wed, Sep 03, 2008 at 02:32:55PM +0000, Christos Zoulas wrote:
> >> In article <20080903134702.GA4485%asim.lip6.fr@localhost>,
> >> Manuel Bouyer  <bouyer%antioche.eu.org@localhost> wrote:
> >> >On Tue, Sep 02, 2008 at 07:45:43PM -0700, Jason Thorpe wrote:
> >> >> Tmpfs?  Do this after file systems have been unmounted?
> >> >
> >> >No, but the proposed in-kernel swapoff code needs access to /dev, which
> >> >may be on a tmpfs. So you can't unmount it before swapoff.
> >> 
> >> Why is that? It does not do a a lookup but accesses the vnode directly
> >> from the swap struct.
> >
> >Hum, I though I read it'd still need the access to /dev, but I couldn't find
> >refeferences to this in this thread. So I may be wrong.
> >
> >I think we still may have a circular dependancy between umount and swapoff
> >if there is swap on a regular file. 
> 
> As I mentioned before, swapoff happens before unmount for that reason.
> The only problem is tmpfs, but that has wired memory?

No, it can also have pageable memory. I think it uses wired memory
for metadata, and pageable memory for file content.

-- 
Manuel Bouyer, LIP6, Universite Paris VI.           
Manuel.Bouyer%lip6.fr@localhost
     NetBSD: 26 ans d'experience feront toujours la difference
--